TY - JOUR

T1 - Metastasis of transgenic breast cancer in plasminogen activator inhibitor-1 gene-deficient mice

AU - Almholt, Kasper

AU - Nielsen, Boye Schnack

AU - Frandsen, Thomas Leth

AU - Brunner, Nils

AU - Danø, Keld

AU - Johnsen, M.

N1 - Keywords: plasminogen activator inhibitor-1 (PAI-1), metastasis, breast cancer, angiogenesis

PY - 2003

Y1 - 2003

N2 - The plasminogen activator inhibitor-1 (PAI-1) blocks the activation of plasmin(ogen), an extracellular protease vital to cancer invasion. PAI-1 is like the corresponding plasminogen activator uPA (urokinase-type plasminogen activator) consistently expressed in human breast cancer. Paradoxically, high levels of PAI-1 as well as uPA are equally associated with poor prognosis in cancer patients. PAI-1 is thought to play a vital role for the controlled extracellular proteolysis during tumor neovascularization. We have studied the effect of PAI-1 deficiency in a transgenic mouse model of metastasizing breast cancer. In these tumors, the expression pattern of uPA and PAI-1 resembles that of human ductal breast cancer and plasminogen is required for efficient metastasis. In a cohort of 63 transgenic mice that were either PAI-1-deficient or wild-type sibling controls, primary tumor growth and vascular density were unaffected by PAI-1 status. PAI-1 deficiency also did not significantly affect the lung metastatic burden. These results agree with the virtual lack of spontaneous phenotype in PAI-1-deficient mice and humans and may reflect that the plasminogen activation reaction is not rate limiting for tumor vascularization and metastasis, or that there is a functional redundancy between PAI-1 and other inhibitors of the uPA/plasmin system, masking the effect of PAI-1 deficiency.

AB - The plasminogen activator inhibitor-1 (PAI-1) blocks the activation of plasmin(ogen), an extracellular protease vital to cancer invasion. PAI-1 is like the corresponding plasminogen activator uPA (urokinase-type plasminogen activator) consistently expressed in human breast cancer. Paradoxically, high levels of PAI-1 as well as uPA are equally associated with poor prognosis in cancer patients. PAI-1 is thought to play a vital role for the controlled extracellular proteolysis during tumor neovascularization. We have studied the effect of PAI-1 deficiency in a transgenic mouse model of metastasizing breast cancer. In these tumors, the expression pattern of uPA and PAI-1 resembles that of human ductal breast cancer and plasminogen is required for efficient metastasis. In a cohort of 63 transgenic mice that were either PAI-1-deficient or wild-type sibling controls, primary tumor growth and vascular density were unaffected by PAI-1 status. PAI-1 deficiency also did not significantly affect the lung metastatic burden. These results agree with the virtual lack of spontaneous phenotype in PAI-1-deficient mice and humans and may reflect that the plasminogen activation reaction is not rate limiting for tumor vascularization and metastasis, or that there is a functional redundancy between PAI-1 and other inhibitors of the uPA/plasmin system, masking the effect of PAI-1 deficiency.

U2 - 10.1038/sj.onc.1206601

DO - 10.1038/sj.onc.1206601

M3 - Journal article

VL - 22

SP - 4389

EP - 4397

JO - Oncogene

JF - Oncogene

SN - 0950-9232

IS - 28

ER -